A Christian-run bakery in Northern Ireland is facing legal action after its owners refused to bake a cake with a slogan supporting same sex marriage.

According to The Christian Institute, the McArthur family, who own Ashers Baking Company in the Belfast area, said they could not fulfil the order because it conflicts with their Christian beliefs about marriage being between a man and a woman. Northern Ireland' s Equality Comission is supporting the complainant against the company.

In May, volunteer LGBT activist Gareth Lee asked for a cake to be decorated with the slogan “Support Gay Marriage”. He also wanted a logo of his campaign group QueerSpace and a photo of Sesame Street’s Bert and Ernie in an embrace to be printed on the cake. When the order came through to the head office, the manager and directors decided to decline the request on conscience grounds, and offered Mr Lee a full refund.

Online photographs of a QueerSpace event in May show that the group managed to get a cake decorated in the way they wanted from a different bakery.

Ashers’ 24-year-old general manager Daniel McArthur told the Christian Institute that they were happy to bake cakes for anyone, but could not fulfil that particular order as it clashed with the ethos of the business. “We are Christians and our Christianity reaches to every point of our lives, whether that’s at home or in the day-to-day running of the business,” he said.

Ashers' is named after a verse from the Bible's book of Genesis, which says, “Bread from Asher shall be rich and he shall yield royal dainties.” The company, which was established in Newtownabbey in 1992, has six shops and employs 62 people.

“We thought that this order was at odds with our beliefs, certainly was in contradiction with what the Bible teaches,” McArthur added.

“We thought that was the end of it, but approximately six weeks later we received a letter from the Equality Commission. The Equality Commission’s letter said that we had discriminated against the customer on the grounds of his sexual orientation,” he said.

Northern Ireland's Equality Commission has confirmed that it is supporting Mr Lee, whose cake order was refused by Ashers'. Despite the fact that gay marriage is not legal in Northern Ireland, the company could face prosecution for allegedly being in breach of the Equality Act (Sexual Orientation) Regulations Northern Ireland 2006 which deals with the provision of goods, services and facilities.

“In this case the commission has granted assistance to the complainant, and has written to the company concerned on his behalf. The commission will consider any response before taking further action,” said a spokesman for the Equality Commission (a copy of the letter is available here). Ashers' will be supported by The Christian Institute in any legal action.

The Institute’s Director, Colin Hart, said: “This is a sign of things to come exactly as we predicted.

“All the McArthurs want is to run their bakery according to their Christian beliefs. There won’t be many situations where they need to turn down an order but this is obviously one of them. No one should be forced to use their creative skills to promote a cause which goes against their consciences.The Government repeatedly failed to listen to members of the public, lawyers, constitutional experts even its own MPs when they called for safeguards to protect those who back traditional marriage, whether at work or in business.

"Imagine the uproar if the Equality Commission said that an environmentally-conscious baker had to produce a cake saying 'Support fracking'? Or if they threatened a feminist bakery for refusing to print a 'Sharia for UK' cake?

“Millions of ordinary people who do not agree with gay marriage, face intimidation and the real threat of legal action from the forces of political correctness if they, out of conscience, decline to provide goods or services to campaign groups they do not agree with or support.”

Mr Hart concluded: “The Government must take urgent action to address this injustice by bringing in legislation that would introduce reasonable accommodation to protect those, who for religious or philosophical reasons, believe that marriage is the lifelong union of one man and one woman.”